CyanoFactory, a European consortium to develop technologies needed to advance cyanobacteria as chassis for production of chemicals and fuels

CyanoFactory, Design, construction and demonstration of solar biofuel production using novel (photo)synthetic cell factories, was an R&D project developed in response to the European Commission FP7-ENERGY-2012-1 call “Future Emerging Technologies” and the need for significant advances in both new science and technologies to convert solar energy into a fuel. CyanoFactory was an example of “purpose driven” research and development with identified scientific goals and creation of new technologies. The present overview highlights significant outcomes of the project, three years after its successful completion. The scientific progress of CyanoFactory involved: (i) development of a ToolBox for cyanobacterial synthetic biology; (ii) construction of DataWarehouse/Bioinformatics web-based capacities and functions; (iii) improvement of chassis growth, functionality and robustness; (iv) introduction of custom designed genetic constructs into cyanobacteria, (v) improvement of photosynthetic efficiency towards hydrogen production; (vi) biosafety mechanisms; (vii) analyses of the designed cyanobacterial cells to identify bottlenecks with suggestions on further improvements; (viii) metabolic modelling of engineered cells; (ix) development of an efficient laboratory scale photobioreactor unit; and (x) the assembly and experimental performance assessment of a larger (1350 L) outdoor flat panel photobioreactor system during two seasons. CyanoFactory - Custom design and purpose construction of microbial cells for the production of desired products using synthetic biology – aimed to go beyond conventional paths to pursue innovative and high impact goals. CyanoFactory brought together ten leading European partners (universities, research organizations and enterprises) with a common goal – to develop the future technologies in Synthetic biology and Advanced photobioreactors

Zur Bestimmung des Umfanges von einfachen Zufallsstichproben

Naeve P, Rögner P. Zur Bestimmung des Umfanges von einfachen Zufallsstichproben. Deutsche Lebensmittel-Rundschau. 1971;67(1):15-19

Cold cathode electron beam sources for high-rate PVD

Electron beams (EB) are known to be powerful and versatile tools for materials evaporation and physical vapor deposition (PVD) of thin films. Regardless the beneficial technological features of the EB?PVD, established designs of high-power electron beam sources based upon thermionic emitters as well as their supply and control systems are complex and expensive. Hence, business economics prevent their application in many thin film processes. Alternative EB sources with cold cathodes have nowadays attracted enhanced interest because of their prospects as economic beam sources for a broader spectrum of applications, including PVD. A simple but efficient high-power, cold cathode electron source has been developed and tested recently. Inside this EB gun, a high-voltage glowdischarge (HVGD) is sustained. Ions from the plasma are accelerated in the cathode fall and hit the cathode thus releasing secondary electrons. These electrons gain energy on the reverse path. Beside to the greatly simplified mechanical design and electric supply circuitry, cost reductions result also from the facts that the HVGD beam source does not require differential high-vacuum pumping and that it can be operated in a wide range of acceleration voltages without the need for movable electrodes. Particle-in-cell (PIC) simulations of the HVGD and of the beam formation in a simple geometry have been carried out to study the effects of the electrodes' geometry and of several discharge parameters on the electron-optical characteristics. Understanding the interaction of cathode material and plasma work gas as well as the handling of arc phenomena are crucial for stable operation of the EB source and have been addressed by experimental investigations therefore. Finally, a compact, cost efficient compound evaporator with an integrated beam bending system and a specially shaped vapor aperture will be introduced. It was successfully tested together with a 30 kV / 60 kW HVGD EB gun in evaporation of copper for high-rate metallization of plastics

Electron Microscopic Structural Analysis of Photosystem I, Photosystem II, and the Cytochrome b6/f Complex from Green Plants and Cyanobacteria

Electron microscopy (EM) in combination with image analysis is a powerful technique to study protein structure at low- and high resolution. Since electron micrographs of biological objects are very noisy, substantial improvement of image quality can be obtained by averaging individual projections. Crystallographic and noncrystallographic averaging methods are available and have been applied to study projections of the large protein complexes embedded in photosynthetic membranes from cyanobacteria and higher plants. Results of EM on monomeric and trimeric Photosystem I complexes, on monomeric and dimeric Photosystem II complexes, and on the monomeric cytochrome b6/f complex are discussed.

PVD coating of metallic sheets and strips

PVD coating of metallic sheets and strips opens new potentials for the production of attractive and innovative products with enhanced surface properties. The paper presents the main development steps from the beginning up to the newest results concerning plasma activated high-rate electron beam deposition. Possible new applications are exemplified in connection with actual results of our investigations. We have analysed the technical and technological state-of-the-art in the field of PVD coating of metallic sheets and strips world-wide and derived the actual trends of development. By use of this knowledge the Fraunhofer Institute for Electron Beam and Plasma Technology (FEP), Dresden, has installed a new research and pilot equipment for the in-line deposition of plates and metallic strips - the so-called Maxi. The paper describes this new equipment and outlines its capabilities

Characterization of a redox active cross-linked complex between cyanobacterial photosystem I and soluble ferredoxin.

A covalent stoichiometric complex between photosystem I (PSI) and ferredoxin from the cyanobacterium Synechocystis sp. PCC 6803 was generated by chemical cross-linking. The photoreduction of ferredoxin, studied by laser flash absorption spectroscopy between 460 and 600 nm, is a fast process in 60% of the covalent complexes, which exhibit spectral and kinetic properties very similar to those observed with the free partners. Two major phases with t(1/2) <1 micros and approximately 10-14 micros are observed at two different pH values (5.8 and 8.0). The remaining complexes do not undergo fast ferredoxin reduction and 20-25% of the complexes are still able to reduce free ferredoxin or flavodoxin efficiently, thus indicating that ferredoxin is not bound properly in this proportion of covalent complexes. The docking site of ferredoxin on PSI was determined by electron microscopy in combination with image analysis. Ferredoxin binds to the cytoplasmic side of PSI, with its mass center 77 angstroms distant from the center of the trimer and in close contact with a ridge formed by the subunits PsaC, PsaD and PsaE. This docking site corresponds to a close proximity between the [2Fe- 2S] center of ferredoxin and the terminal [4Fe-4S] acceptor FII of PSI and is very similar in position to the docking site of flavodoxin, an alternative electron acceptor of PSI

Characterization of a redox-active cross-linked complex between cyanobacterial photosystem I and its physiological acceptor flavodoxin.

A covalent complex between photosystem I and flavodoxin from the cyanobacterium Synechococcus sp. PCC 7002 was generated by chemical cross-linking. Laser flash-absorption spectroscopy indicates that the bound flavodoxin of this complex is stabilized in the semiquinone state and is photoreduced to the quinol form upon light excitation. The kinetics of this photoreduction process, which takes place in approximately 50% of the reaction centres, displays three exponential components with half-lives of 9 microsec, 70 microsec and 1 ms. The fully reduced flavodoxin subsequently recombines with P700+ with a t1/2 of 330 ms. A corresponding flavodoxin semiquinone radical signal is readily observed in the dark by room temperature electron paramagnetic resonance, which reversibly disappears upon illumination. In contrast, the light-induced reduction of oxidized flavodoxin can be observed only by first-flash experiments following excessive dark adaptation. In addition, the docking site of flavodoxin on photosystem I was determined by electron microscopy in combination with image analysis. Flavodoxin binds to the cytoplasmic side of photosystem I at a distance of 7 nm from the centre of the trimer and in close contact to a ridge formed by the subunits PsaC, PsaD and PsaE